SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b715e66ba46803f6a41ed8d8450eef31db7e597f82ac8131d6edf114a0916c8d' 
  AND token = 'hS2dTc/1OLkwR0x0U4QR0DosnNgDXFFW8bzTrEO2FPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}